Hydraulic boom particularly for blast hole drilling methods



Oct. 7, 1969 L- ARCANGELI HYDRAULIC BOOM PARTICULARLY FOR BLAST HOLE DRILLING METHODS Filed April 4, lse 4 2 Sheets-Sheet 1 INVENTOR. 'RYccm 99.

Oct. 7, 1969 L. ARCANGELI HYDRAULIC BOOM PARTICULARLY FOR BLAST HOLE DRILLING METHODS 2 Sheets-Sheet Filed April 4, 1968 United States Patent US. Cl. 173-43 3 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a hydraulic boom for drilling holes, including a supporting assemblage, a swingable boom member supported by said supporting assemblage, a cradle member hingedly supported on one end of said boom member and having a feed member, slidably supporting a drill and power and control means for actuating and controlling the movement of the movable parts of the hydraulic boom and the drill. The hydraulic boom arrangement provides for powered adjustment of the cradle member about vfive pivot points relative to the supporting assemblage. The adjustment about two of the pivot points is interrelated by a closed hydraulic servo arrangement.

BACKGROUND OF THE INVENTION This invention relates to a hydraulic boom particularly for blast hole drilling methods for mining and tunneling.

It is known that in blast hole drilling methods the distribution or coverage pattern of the drilling holes isof utmost importance. This pattern is variable depending on a number of operative conditions. In addition the ,direction of the drilling holes may also vary and in one and the same pattern both parallel and mutually inclined drilling holes may be adopted.

As a consequence the versatility requirements for hydraulic booms are very exacting.

One of the requirements for hydraulic booms of this type is to reduce the so-called blind spots or those areas of a surface, which cannot be correctly reached by a boom, to a minimum.

For the purpose hydraulic booms have been devised having component parts arranged to be displaced according to Cartesian coordinates. Such known booms are very complicated and their setting is time consuming since they require a great number of steering operations for reaching the selected drilling spot, with a correct setting of the drill.

SUMMARY OF THE INVENTION An object of this invention is to provide a highly versatile hydraulic boom, simple in structure and reliable in operation which will be able practically to eliminate the so-called blind spots and will be able to cover a drilling hole pattern of any kind and which will reduce the number of steering or setting operations and the time and effort for reaching a drilling spot to a minimum.

These objects are attained by a hydraulic boom for drilling holes, including a supporting assemblage, a swingable boom member supported by said supporting assemblage, a cradle member hingedly supported on one end of said boom member and having a feed member slidably supporting a drill and power and control means for actuating and controlling the movement of the movable parts of the hydraulic boom and the drill and wherein the improvement comprises a first connecting group between said boom member and said supporting assemblage and rotatably connecting thereto one end of said boom member, said first connecting group having first 3,470,969 Patented Oct. 7, 1969 pivot means allowing rotation of said boom member thereabout and defining a first axis of rotation, second pivot means allowing rotation of said boom member thereabout and defining a second axis of rotation perpendicular to said first axis of rotation, and third pivot means allowing rotation of said boom member thereabout and defining a third axis of rotation perpendicular to said second axis of rotation, and wherein the improvement further comprises a second connecting group at a free end of said boom member opposite to said one end thereof and rotatably connecting said free end with said cradle member, said second connecting group having fourth pivot means allowing rotation of said cradle member thereabout and defining a fourth axis of rotation substantially parallel to said third axis of rotation, said second connecting group having further fifth pivot means allowing rotation of said cradle member and defining a fifth axis of rotation perpendicular to said fourth axis of rotation, and wherein the improvement further comprises a hydraulic servo arrangement between said fourth pivot means and said third pivot means, said servo arrangement being responsive to the rotation of said third and the fourth pivot means.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the invention will be described hereinafter with reference to the accompanying drawing in which:

FIG. 1 illustrates, in perspective view, the preferred embodiment of the hydraulic boom of this invention;

FIG. 2 shows diagrammatically in symbolic representation the assembly of the hydraulic boom shown in FIG. 1.

FIGS. 3, 4 and 5 show different settings of the shown hydraulic boom in a vertical plane, and in symbolic representation.

FIG. 6 shows a plan view of the hydraulic boom of FIG. 1 in a diverse scale and with different settings of the cradle member in a horizontal plane.

FIG. 7 shows diagrammatically in symbolic representation different settings of the boom and cradle member;

FIG. 8 shows in a perspective view one of the hydraulic actuators of the servo arrangement.

FIG. 9 shows a front view partly in section of one embodiment of a first connecting group for the boom member.

FIG. 10 shows a hydraulic jack connection for swinging the cradle member.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawing the supporting assemblage of the boom comprises two supports 1 and 2 and a vehicle or a jumbo of which a portion of the baseplate 3 can be seen (FIG. 2) on Which' said supports are fixed. In said supports 1 and 2 a vertical pin 4 is pivotally supported for rotation.

. one or more hydraulic cylinders 5 (FIGS. 1 and 6). The

hydraulic cylinder 5 is pivoted to a part of the jumbo 3, and its attendant piston 5' is pivotally connected to a lug of the connecting group 4a in a point offset with respect to said pin 4. Supported by the pin 4 is a sleeve 6 on which a hydraulic motor 7' which actuates a worm screw 7 is supported. Journalled in the axial bore' of the sleeve 6 and coaxial therewith is a shaft 8 on which a gear 9 is keyed. The shaft 8 defines a second pivot means having an axis of rotation perpendicular to the axis of rotation defined by said first pivot means 4. The gear 9 meshes with the worm 7 and is driven thereby in rotation also through a full circle of 360 in either direction. In rigid relation with the shaft 8 is a fork member 10 which, through a pivot connection 11, pivotally carries the boom 12 proper and pivotally carries at a point 13 a hydraulic cylinder 14 controlling the swinging of said boom 12. The pivot connection 11 defines a third pivot means having an axis of rotation perpendicular to the axis of rotation of the shaft 8.

The boom 12 may have a fixed length, however in more sophisticated embodiments, such as the illustrated one, the boom 12 can be fitted with a power cylinder 15 so as to permit an extension and retraction of the boom member. Pivoted in 24 at the free end of the boom member 12 is a short arm 16 which bears the feed unit. The feed unit may be of any known type and is briefly described hereinafter so as to facilitate the understanding of the operability of the hydraulic boom of this invention. Pivotally connected to the free end of the short arm 16, via a pivot 17, is a feed-carrying cradle 18 which can be rotated about the pivot 17 by means of a power cylinder 19, arranged offset with respect to the pivot 17 and hingedly connected with one end thereof to a lateral lug of the short arm 16 and with the free end of its piston rod to a lateral lug of the cradle 18.

The short arm 16, pivots 24 and 17 and the servo mechanism 26 to be described are parts of a second connecting group connecting the free end of the boom mem-, ber 12 to the cradle member 18. The cradle 18 has guide;- ways on which, with the aid of a hydraulic power cylin der 20, the feed 21 can be slid. The feed carries a drill 22 actuated, as is conventional, by a power mechanism 23. One of the outstanding novel features of the present invention lies in that, both on the pivotal point 11 for pivoting the boom 12 and on the pivotal point 24 for pivoting the arm or supporting member 16 which carries the feed unit, there are mounted a pilot hydraulic actuator 25 and a piloted hydraulic actuator 26, respectively of the servo-mechanism-like type, both substantially of the type shown in FIG. 8. The two rotary actuators 25 and 26 are hydraulically mutually connected in interlocked or closed circuit by means of scaled ducts 27. The interlocked hydraulic actuators comprise each at least one cylinder 25a, a piston 25b slidable in said cylinder 25a, a shaft 11 or 24 journalled in a housing 25d integral with the cylinders 25a. On the shaft 11 or 24 a pinion 25g is provided in mesh with a rack section 25c rigid with the piston 25b. Through the pipe connections 25e and 25 two distant actuators of this type are connected by two pipes 27. It will be understood that, when the housing 25d is rotated about the shaft 11 (24) together with the cylinder 25a, the piston 25!; is displaced along the cylinder by virtue of the meshing teeth of the pinion 25g and rack 250. At the same time the pressure liquid within the cylinder is compressed on one side of the piston and depressed at the other side thereof. Due to the pipe connection this hydraulic action is transmitted to the distant actuator which is forced to perform piloted operations induced by the first actuator.

The shaft 11 of the pilot actuator 25 may be fastened to the fork 10, whereas the respective cylinder may be fixed on the boom 12. The shaft 24 of the piloted actuator 26 may be affixed to the free end of the boom 12 and its attendant cylinder 26 may be affixed on, and cause the rotation of the arm 16 which carries the feed unit. Furthermore, the described hydraulic boom has abutments or stops 28 and 29 intended to hold said boom in a substantially horizontal position when the fiuid pressure drops beyond a certain value.

The closed hydraulic circuit between the two actuators 25 and 26 is connected through valve means with the general hydraulic circuits of the hydraulic power mechanisms. This circuit may be of any known kind and the relative valve means may be so arranged and controlled that the interlocking relation between the two actuators is released to enable them to rotate independently or to change the setting of the respective component parts.

It will be appreciated that by virtue of these servo-like actuators the swinging of the boom member does not cause any variation in the angular setting of the cradle 18, since any rotation in a vertical plane of the boom member 12 induces through the actuators 25, 26 a rotation in opposite direction of the cradle. In this way, when the cradle is set to assume a horizontal position it remains with a horizontal setting independently from the swinging movement of the boom-member 12 in a vertical plane. This greatly simplifies the operation of the boom and reduces the number of steering operation and the time necessary for covering a selected drilling pattern.

The described boom is enabled to effect, by means of hydraulic controls, the following movements which are also illustrated, by arrows A through G, in FIG. 1 of the drawing:

(A) a swinging movement of the boom in a horizontal plane.

(B) a rotational movement of the boom about the shaft 8.

(C) a lifting rotational movement of the boom in a vertical plane.

(D) a movement of extension.

(E) a dumping movement of the feed in a vertical plane.

(F) a tilting movement of the feed in a horizontal plane.

(G) a sliding movement of the feed towards and away of the digging front area.

In the actuators 25 and 26, the cross-sectional areas of the respective cylinders may be equal, so that, to a movement of the pilot actuator 25 an equally opposite movement of the piloted actuator 26 may correspond.

It will be apreciated thus that the setting of the boom is carried out mainly according to polar coordinates and the so-called blind spots are practically eliminated.

The size of the power cylinder 14, two of which are advantageously provided on both sides of the boom member 12, and of its piston 14", its piston rod 14' and its hinged connection 13 and 14a, are so selected as to overcome the possible resisting forces created by the hydraulic actuators 25, 26.

I claim:

1. A hydraulic boom for drilling holes, including a supporting assemblage, a swingable boom member supported by said supporting assemblage, a cradle member hingedly supported on one end of said boom member and having a feed member slidably supporting a drill and power and control means for actuating and controlling the movement of the movable parts of the hydraulic boom and the drill and wherein the improvement comprises a first connecting group between said boom member and said supporting assemblage and rotatably connecting thereto one end of said boom member, said first connecting group having first pivot means allowing rotation of said boom member thereabout and defining a first axis of rotation, second pivot means allowing rotation of said boom member thereabout and defining a second axis of rotation perpendicular to said first axis of rotation, and third pivot means allowing rotation of said boom member thereabout and defining a third axis of rotation perpendicular to said second axis of rotation, and wherein the improvement further comprises a second connecting group at .a free end of said boom member opposite to said one end thereof and rotatably connecting said free end with said cradle member, said second connecting group having fourth pivot means allowing rotation of said cradle member thereabout and defining a fourth axis of rotation substantially parallel to said third axis of rotation, said second connecting group having further fifth pivot means allowing rotation of said cradle member and defining a fifth axis of rotation perpendicular to said fourth axis of rotation, and wherein the improvement further comprises a hydraulic servo arrangement between said fourth pivot means and said third pivot means, said servo arrangement being responsive to the rotation of said third and the fourth pivot means.

2. A boom according to claim 1, wherein said second pivot means is a shaft having a toothed gear supported thereon, and wherein said first connecting group includes a worm gear in mesh with said toothed gear and hydraulic motor actuating said worm gear.

3. A boom according to claim 1, wherein said hydraulic servo arrangement comprises a first hydraulic actuator including shaft coinciding with said third pivot means and having a pinion mounted thereon, a cylinder rotatable thereabout and a piston with a rack section rigid therewith and in mesh with said pinion, said hydraulic servo arrangement comprising further a second hydraulic actuator including a shaft coinciding with said fourth pivot means and having a pinion mounted thereon, a cylinder rotatable thereabout and having a piston with a rack section rigid therewith and in mesh with said pinion, and duct means providing hydraulic communication between said cylinders.

5 References Cited UNITED STATES PATENTS 2,638,326 5/1953 Lehner 173-43 3,226,064 12/1965 Thompson 173-43X 10 3,374,975 3/1968 Bronder 173-38 X ERNEST R. PURSER, Primary Examiner US. Cl. X.R. 

